Fifty per cent of people do not know which groups would be at risk from over-the-counter painkillers.

A survey of 2,000 people by independent polling group Omnibus showed half did not know what ingredients were in the everyday medicines.

Educational group CAMPAIGN, the Children, Asthmatics and Mums Paracetamol Information Network is being launched to promote better information.

It says at-risk groups who take non-steroidal anti-inflammatory drugs (NSAIDs), such as aspirin and ibuprofen could be at risk of making their condition worse.

"As a nation, we pop all sorts of pills with a remarkable lack of understanding of what we're taking

Dr Trisha Macnair

Launching CAMPAIGN, Dr Trisha Macnair, a former hospital doctor and BBC Health website doctor said people needed more information about the pills they were taking.

"As a nation, we pop all sorts of pills with a remarkable lack of understanding of what we're taking.

"In a hundred and one situations, that's potentially life threatening - to not know what medications we're taking," she said.

"Educating people in the appropriate use of pain relievers and alerting them to the three vulnerable groups highlighted by the CAMPIGN is key to the prevention of potentially serious side effects."

And she added paracetamol should be the first-line analgesic for children under 12, breastfeeding mums and asthmatics.

The group is sponsored by SmithKline Beecham, makers of Panadol, and other paracetamol based products.

Asthma risk

Asthmatics could be the group most at risk. CAMPAIGN quotes a recent survey which showed 45% did not realise that taking certain over-the-counter pain relievers may make their asthma worse.

Dr John Costello, consultant physician at the department of respiratory medicine at King's College Hospital, London, said: "Too few asthmatics are aware of the potential problems that occur as a result of using aspirin or NSAIDS (for example ibuprofen).

A spokeswoman for the National Asthma Campaign said research showed 3% of asthma sufferers were at risk of having a severe attack if they took aspirin or NSAIDs.

She said: "Paracetamol is safer for people with asthma than aspirin or NSAIDs. The risk with paracetamol is less, especially if its only taken in low doses."